Arab ruler consumed by the mirage (4)
I believe the answer is:
emir
'arab ruler' is the definition.
(I've seen this before)
'consumed by the mirage' is the wordplay.
'consumed by' indicates the answer is hidden within the clue (I've seen this in other clues).
'EMIR' is hidden in the letters of 'the mirage'.
(Other definitions for emir that I've seen before include "Arab leader" , "eader abroad?" , "Eastern ruler in mire" , "Ruler or chieftain in Arabia" , "Local chief" .)